Information recognition device operating with low power consumption

ABSTRACT

A character recognition device recognizing characters with low power consumption includes a data input unit for entering handwriting data representing a character to be recognized, a character recognition dictionary storing character recognition information required for character recognition as well as operating frequency information concerning the operating frequency of the character recognition device that is set in connection with the recognition processing, a character recognition processing unit recognizing the character based on the handwriting data and the character recognition information, a recognition result output unit which outputs the character recognized by the character recognition processing unit, and a power management unit changing the operating frequency of the character recognition processing unit based on the operating frequency information stored in the character recognition dictionary.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device which recognizes suchinformation as characters and voice and, in particular, to aninformation recognition device which is controlled based on charactersand voice to be recognized and accordingly achieves an effectivereduction of power consumption.

2. Description of the Background Art

For battery-driven mobile information terminals that have recently beenincreasing in number, the battery time is considered as an importantfactor and thus reduction of the power consumption of the devices is anessential challenge in development. Then, there arises a severerrequirement for reduction of the power consumption of a characterrecognition device and a voice recognition device that are incorporatedinto the mobile information terminals. Japanese Patent Laying-Open No.7-244494 discloses a voice recognition device capable of recognizingvoice in operating with low power consumption. This voice recognitiondevice includes: a pre-processing circuit receiving an input voice totransmit feature pattern data containing a feature amount in a voicesection of the input voice signal; similarity comparison anddetermination circuit connected to the pre-processing circuit tocompare, in terms of similarity, the feature pattern data with referencepattern data for a plurality of voices that is stored in advance todetermine the degree of similarity therebetween, based on a clocksignal; and a control circuit having its input connected to thepre-processing circuit and the similarity comparison and determinationcircuit and having its output connected to the similarity comparison anddetermination circuit to decrease the frequency of the clock signallower than a reference frequency if the resultant determination as tothe similarity does not indicate a predetermined voice candidate or novoice is input in at least a certain time period.

The above voice recognition device can reduce the power consumption bydecreasing the frequency of the clock signal lower than a referencefrequency thereby decreasing the operating speed of the similaritycomparison and determination circuit when, for example, no voice isinput in at least a certain time period. Even if the similaritycomparison and determination circuit operates with the reduced powerconsumption, it can still recognize voice since the clock signal isprovided to the circuit.

The disclosed voice recognition device decreases the frequency of theclock signal lower than a reference frequency when a predetermined voicecandidate cannot be obtained or no voice is input in at least a certaintime period. For the battery-driven mobile information terminal, moredelicate power control is necessary in order to extend the battery time.As the mobile information terminal has increased functions, theoperating frequency of a microcomputer provided in the mobileinformation terminal becomes higher, which tends to result in increasein power consumption. Therefore, the control as disclosed in the abovepatent document cannot achieve delicate power control in operation andis thus unsatisfactory as a measure to decrease the power consumption.

SUMMARY OF THE INVENTION

One object of the present invention is to provide an informationrecognition device capable of recognizing characters with low powerconsumption.

Another object of the present invention is to provide an informationrecognition device capable of recognizing characters with low powerconsumption based on handwriting of a user.

Still another object of the present invention is to provide aninformation recognition device capable of recognizing voice with lowpower consumption.

A further object of the present invention is to provide an informationrecognition device capable of recognizing voice with low powerconsumption based on voice of a user.

A further object of the present invention is to provide an informationrecognition device readily capable of changing the language ofcharacters to be recognized.

An information recognition device according to one aspect of the presentinvention includes an input unit for entering handwriting datarepresenting a character to be subjected to recognition processing, astorage unit storing first information required for recognition of thecharacter by a character recognition module and second informationconcerning power consumption of the information recognition device thatis set in connection with the recognition processing, the characterrecognition module recognizing the character based on the handwritingdata and the first information, an output unit outputting the characterrecognized by the character recognition module, a power management unitmanaging power consumption of the information recognition device, and acontrol module controlling the power management unit based on the secondinformation.

An information recognition device according to another aspect of thepresent invention includes an input unit for entering voice datarepresenting voice to be subjected to recognition processing, a storageunit storing first information required for voice recognition by a voicerecognition module and second information concerning power consumptionof the information recognition device that is set according to voice tobe recognized, the voice recognition module recognizing voice based onthe voice data entered from the input unit and the first informationstored in the storage unit, an output unit outputting the voicerecognized by the voice recognition module, a power management unitmanaging power consumption of the information recognition device, and acontrol module controlling the power management unit based on the secondinformation stored in the storage unit.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a control block diagram of a character recognition deviceaccording to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control structure of a program executedby a control unit in FIG. 1.

FIG. 3 is a control block diagram of a character recognition deviceaccording to a second embodiment of the present invention.

FIG. 4 shows operating frequency information shown in FIG. 3.

FIG. 5 is a flowchart showing a control structure of a program executedby a control unit in FIG. 3.

FIG. 6 is a control block diagram of a character recognition deviceaccording to a third embodiment of the present invention.

FIG. 7 shows operating frequency information shown in FIG. 6.

FIG. 8 is a flowchart showing a control structure of a program executedby a control unit in FIG. 6.

FIG. 9 is a control block diagram of a character recognition deviceaccording to a fourth embodiment of the present invention.

FIG. 10 shows operating frequency information in FIG. 9.

FIG. 11 is a flowchart showing a control structure of a program executedby a control unit in FIG. 9.

FIG. 12 is a flowchart showing a control structure of a program executedby a narrow-down character recognition processing unit in FIG. 9.

FIG. 13 is a control block diagram of a character recognition deviceaccording to a fifth embodiment of the present invention.

FIG. 14 shows operating frequency information shown in FIG. 13.

FIG. 15 is a flowchart showing a control structure of a program executedby a control unit in FIG. 13.

FIG. 16 is a control block diagram of a power management circuit of acharacter recognition device according to a sixth embodiment of thepresent invention.

FIG. 17 is a control block diagram of a character recognition deviceaccording to a seventh embodiment of the present invention.

FIG. 18 is a flowchart showing a control structure of a program executedby a control unit in FIG. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention are now described with reference tothe drawings. In the following description, the same components aredenoted by the same reference character and identified by the same nameand have the same function, and therefore detailed description thereofis not repeated here.

First Embodiment

A character recognition device according to this embodiment ishereinafter described.

Referring to FIG. 1, the character recognition device includes acharacter recognition dictionary 100 for use in a character recognitionprocess, a data input unit 200 which is a touch panel for example forallowing a user to enter a character which the user desires to berecognized, a character recognition processing unit 300 performingcharacter recognition processing by referring to character recognitiondictionary 100 based on handwriting data supplied from data input unit200, a recognition result output unit 400 which is a display for exampleto output the result of character recognition by character recognitionprocessing unit 300, a control unit 600 controlling, via a control line700, character recognition dictionary 100, data input unit 200,character recognition processing unit 300, and recognition result outputunit 400, and a power management unit 500 controlling, via a controlline 800, the operating frequency and the operating mode of data inputunit 200, character recognition processing unit 300 and recognitionresult output unit 400.

Character recognition dictionary 100 is configured to be adapted for onelanguage, as Japanese version, Chinese version, Korean version, Englishversion or the like, and stored in a memory card for example. The memorycard in which character recognition dictionary 100 is stored isdetachably held in a card slot of the character recognition device.Character recognition dictionary 100 can thus be replaced to allow thecharacter recognition device to be adaptable for multiple languages.Character recognition dictionary 100 stores operating frequencyinformation 900. The stored operating frequency information 900 includesan average clock number necessary for the recognition processing as wellas an average processing time for each operating frequency when acharacter is recognized by means of character recognition dictionary100.

Control unit 600 calculates, by using operating frequency information900, an optimum operating frequency of data input unit 200, characterrecognition processing unit 300 and recognition result output unit 400of the character recognition device to output an instruction to powermanagement unit 500 to set the calculated operating frequency. Theoptimum operating frequency here refers to a minimum operating frequencywhich is required for keeping an average time for character recognitionprocessing within a predefined time. The character-recognitionprocessing time depends on the number of characters to be recognizedthat are registered in character recognition dictionary 100. Therefore,as the operating frequency information, a smaller dock number is storedfor a character recognition dictionary containing a smaller number ofcharacters to be recognized.

Data input unit 200 is formed of a touch panel for example by which auser can enter handwriting with a finger or a pen. Further, data inputunit 200 can process the entered handwriting as a coordinate datastring.

Character recognition processing unit 300 performs character recognitionprocessing for the coordinate data string input from data input unit 200by referring to character recognition dictionary 100.

Referring to FIG. 2, a control structure of a program executed bycontrol unit 600 in FIG. 1 is described.

In step (hereinafter abbreviated to S) 100, control unit 600 calculatesan optimum operating frequency based on operating frequency information900 stored in character recognition dictionary 100 and sets thecalculated frequency in power management unit 500.

In S200, control unit 600 instructs data input unit 200 to takecoordinate data. In S300, control unit 600 determines whether data isentered or not. If data is entered (YES in S300), the process proceedsto S400. If not (NO in S300), the process proceeds to S500.

In S400, control unit 600 inputs the coordinate data to characterrecognition processing unit 300 to perform recognition processing.

In S500, control unit 600 determines whether or not data is entered intodata input unit 200 in a predetermined period. If data is not entered inthe predetermined period (NO in S500), the process proceeds to S700. Ifdata is entered in the predetermined period (YS in S500), the processreturns to S200.

In S600, control unit 600 uses recognition result output unit 400 tooutput the result of recognition by character recognition processingunit 300. After this, the process returns to S200 to carry out characterrecognition processing for subsequent handwriting data entered into datainput unit 200.

In S700, control unit 600 instructs power management unit 500 to stopclock generation, namely to shift the operating mode to a low-powermode. In S800, control unit 600 determines whether or not the characterrecognition device should be returned to a normal mode. In this case, itis determined that the mode should be returned to the normal mode when,for example, handwriting data is entered into data input unit 200 or auser pushes a specific button. For return to the normal mode (YES inS800), the process proceeds to S900. If not (NO in S800), the processreturns to S800 to wait for the timing of returning to the normal mode.

In S900, control unit 600 instructs power management unit 500 to resumeclock generation. The process thereafter returns to S200.

An operation of the character recognition device in this embodimentbased on the above-discussed structure and flowchart is described below.

Character recognition dictionary 100 is inserted into the memory cardslot of the character recognition device which is then powered, controlunit 600 calculates an optimum operating frequency based on theoperating frequency information stored in character recognitiondictionary 100, and the calculated operating frequency is set in powermanagement unit 500 (S100). At this time, the operating frequency is setin power management unit 500 according to the operating frequency whichis set correspondingly to the number of characters to be recognizedstored in character recognition dictionary 100 for each language. Powermanagement unit 500 then sets the operating frequency of such componentsas data input unit 200, character recognition processing unit 300 andrecognition result output unit

When a user enters handwriting data from data input unit 200 such astouch panel or tablet (S200), coordinate data is input to characterrecognition processing unit 300 which then performs recognitionprocessing (S400). The result of recognition by character recognitionprocessing unit 300 is output from recognition result output unit 400(S400).

In the above-described operation, if handwriting data is not enteredfrom data input unit 200 in a predetermined period (NO in S500), controlunit 600 instructs power management unit 500 to stop clock generationand shift the operating mode of the character recognition device to alow-power mode (S700). When a user pushes a specific button or entershandwriting data from data input unit 200, it is determined that thedevice should be returned to a normal mode (YES in S800) and controlunit 600 instructs power management unit 500 to resume clock generation(S900).

As discussed above, the character recognition dictionary of thecharacter recognition device in this embodiment stores the operatingfrequency information corresponding to the number of characters to berecognized. If the character recognition dictionary contains a smallnumber of characters to be recognized, the control unit sets a loweroperating frequency in the power management unit. A lower operatingfrequency results in a smaller power consumption, therefore, the powerconsumption can be reduced by changing the operating frequency based onthe operating frequency information stored in the character recognitiondictionary.

Second Embodiment

A character recognition device according to a second embodiment of thepresent invention is hereinafter described.

Referring to FIG. 3, a control block diagram of the characterrecognition device in this embodiment is described. It is noted that anycomponent in the control block diagram shown in FIG. 3 that is the sameas the corresponding one in FIG. 1 is denoted by the same referencecharacter, has the same function, and thus detailed description thereofis not repeated here.

Referring to FIG. 3, the character recognition device in this embodimentincludes a control unit 610 executing a program different from that ofcontrol unit 600 of the character recognition device in theabove-discussed first embodiment, and operating frequency information910 different from operating frequency information 900 and furtherincludes a character type setting unit 1000 for setting the type ofcharacters to be recognized that is not included in the characterrecognition device in the first embodiment.

Control unit 610 executes a program different from that of control unit600 of the character recognition device in the first embodimentdiscussed above. Further, as shown in FIG. 4, operating frequencyinformation 910 stored in character recognition dictionary 100 includesfrequency setting information for each type of characters to berecognized. For example, the frequency setting information is stored insuch a way that, if the type of characters to be recognized is limitedto Hiragana, the frequency setting information is “FA (1)” and, if thetype of characters to be recognized is limited to Katakana, thefrequency setting information is “FA (2)”.

Character type setting unit 1000 is an input unit for allowing a user toset the type of characters to be recognized by this characterrecognition device. For example, the type of characters to be recognizedis set by limiting it to Hiragana, Katakana or Kanji as shown in FIG. 4,or to English characters only, alphanumerics only or numerals only, forexample.

Referring to FIG. 5, a control structure of a program executed bycontrol unit 610 of the character recognition device in this embodimentis described. It is noted that any process step in the flowchart shownin FIG. 5 that is the same as the corresponding one in FIG. 2 isindicated by the same step number, the processing therein is the same,and thus detailed description thereof is not repeated here.

In S2000, control unit 610 obtains, from character type setting unit1000, the type of characters to be recognized that is currently set.

In S2100, control unit 610 calculates an optimum operating frequencybased on the operating frequency information corresponding to the typeof characters to be recognized, and sets the calculated frequency inpower management unit 500.

An operation of the character recognition device in this embodimentbased on the above-discussed structure and flowchart is described below.

When a user uses character type setting unit 1000 to limit the type ofcharacters to be recognized to Katakana only, operating frequency “FA(2)” is selected that is the frequency setting information correspondingto Katakana as the type of characters to be recognized shown in FIG. 4,and the selected frequency is set in power management unit 500 (S2100).

At the operating frequency which is set as described above, data inputunit 200, character recognition processing unit 300 and recognitionresult output unit 400 operate. Based on handwriting data entered intodata input unit 200, character recognition processing unit 300 performscharacter recognition. The result of recognition by characterrecognition processing unit 300 is then output from recognition resultoutput unit 400.

As discussed above, the character recognition device in this embodimentincludes, in the character recognition dictionary, the operatingfrequency information for each type of characters to be recognized. Thecontrol unit can set an optimum operating frequency appropriate for thetype of characters before the character recognition processing iscarried out. Consequently, processing at unnecessarily high speed can beavoided and the power consumption can be reduced by making the operatingfrequency as low as possible.

Third Embodiment

A character recognition device according to a third embodiment of thepresent invention is hereinafter described.

Referring to FIG. 6, a control block diagram of the characterrecognition device in this embodiment is described. It is noted that anycomponent in the control block diagram shown in FIG. 6 that is the sameas the corresponding one in FIG. 1 is denoted by the same referencecharacter, has the same function, and thus detailed description thereofis not repeated here.

Referring to FIG. 6, the character recognition device in this embodimentincludes a control unit 620 executing a program different from that ofcontrol unit 600 of the character recognition device in theabove-discussed first embodiment, and a character recognition dictionary100 storing operating frequency information 920 different from operatingfrequency information 900 in the first embodiment.

As shown in FIG. 7, the stored operating frequency information 920includes frequency setting information stored for each number of strokesof handwriting data entered in data input unit 200. For example, thefrequency setting information is stored in such a way that the operatingfrequency is “FB (N)” when the number of strokes of a character is “N”.Here, a lower operating frequency is set for a smaller number of strokesas shown in FIG. 7.

Referring to FIG. 8, a control structure of a program executed bycontrol unit 620 of the character recognition device in this embodimentis described. It is noted that any process step in the flowchart shownin FIG. 8 that is the same as the corresponding one in FIG. 2 isindicated by the same step number, the processing in the step is thesame, and thus detailed description thereof is not repeated here.

In S3000, control unit 620 obtains the number of strokes from data inputunit 200 to calculate an optimum operating frequency based on theoperating frequency information corresponding to the number of strokes,and sets the calculated frequency in power management unit 500.

An operation of the character recognition device in this embodimentbased on the above-discussed structure and flowchart is described below.

When data is entered into data input unit 200 (YES in S300), controlunit 620 obtains the number of strokes from handwriting informationentered into data input unit 200 and calculates an optimum operatingfrequency based on the operating frequency information corresponding tothe number of strokes. The calculated optimum operating frequency is setin power management unit 500. In this way, based on the number ofstrokes of handwriting data entered into data input unit 200, theoperating frequency is set at which data input unit 200, characterrecognition processing unit 300 and recognition result output unit 400operate.

Coordinate data entered to data input unit 200 is input to characterrecognition processing unit 300 which then performs characterrecognition processing (S400), and the result of recognition is outputfrom recognition result output unit 400 (S600).

As discussed above, the character recognition device in this embodimenthas, in the character recognition dictionary, the operating frequencyinformation for each number of strokes. The control unit can thus set anoptimum operating frequency appropriate for the number of strokes of theentered handwriting data before execution of the character recognitionprocessing. Accordingly, processing at an unnecessarily high speed canbe avoided. Moreover, as the operating frequency is set as low aspossible, the power consumption can be reduced.

Fourth Embodiment

A character recognition device according to a fourth embodiment of thepresent invention is hereinafter described.

Referring to FIG. 9, a control block diagram of the characterrecognition device in this embodiment is described. It is noted that anycomponent in the control block diagram shown in FIG. 9 that is the sameas the corresponding one in FIG. 1 is denoted by the same referencecharacter, has the same function, and thus detailed description thereofis not repeated here.

As shown in FIG. 9, the character recognition device in this embodimentincludes a control unit 630 executing a program which is different fromthat of control unit 600 of the character recognition device in theabove-discussed first embodiment, a narrow-down character recognitionprocessing unit 310 carrying out processing different from that ofcharacter recognition processing unit 300, and a character recognitiondictionary 100 storing operating frequency information 930 differentfrom operating frequency information 900.

Operating frequency information 930 as shown in FIG. 10 includesfrequency setting information stored correspondingly to the number ofcandidates that are narrowed down for a character to be recognized bynarrow-down character recognition processing unit 310. (This number ishereinafter referred to as “narrow-down number”). For example, thefrequency setting information is stored in such a way that, if thenarrow-down number is “N”, the operating frequency is “FC (N)”. Here, alower operating frequency is set for a smaller narrow-down number whichis determined by narrow-down character recognition processing unit 310,as shown in FIG. 10.

Narrow-down character recognition processing unit 310 checks featureparameters of handwriting data supplied from data input unit 200 againstcharacter recognition dictionary 100 to narrow down, step-by-step,candidates for a character to be recognized thereby performing characterrecognition processing. In the process of stepwise narrow-down characterrecognition, the operating frequency is changed according to thenarrow-down number of characters.

Referring to FIG. 11, a control structure of a program executed bycontrol unit 630 of the character recognition device in this embodimentis described. It is noted that any process step in the flowchart shownin FIG. 11 that is the same as the corresponding one in FIG. 2 isindicated by the same step number, the processing therein is the same,and thus detailed description thereof is not repeated here.

In S4000, control unit 630 inputs coordinate data to narrow-downcharacter recognition processing unit 310 to perform recognitionprocessing. This recognition processing is detailed hereinafter. InS4100, control unit 630 uses recognition result output unit 400 tooutput the result of recognition by narrow-down character recognitionprocessing unit 310.

Referring to FIG. 12, a control structure of a program executed bynarrow-down character recognition processing unit 310 of the characterrecognition device in this embodiment is described.

In S4010, narrow-down character recognition processing unit 310 extractsfeature parameters. At this time, based on handwriting data entered fromdata input unit 200, the feature parameters are extracted. In S4020,narrow-down character recognition processing unit 310 carries out afirst stage of a process of narrowing down candidates for a character.Here, the feature parameters extracted in S4010 and informationcorresponding to the feature parameters that is stored in characterrecognition dictionary 100 are used.

In S4030, narrow-down character recognition processing unit 310calculates an optimum operating frequency based on operating frequencyinformation corresponding to the result of narrowing down candidates andthen sets the calculated frequency in power management unit 500. At thistime, as shown in FIG. 10, the operating frequency is set in powermanagement unit 500 in such a way that, if the narrow-down number is“20”, the operating frequency is “FC (2)”.

The above-described process of narrowing down candidates is repeatedstep-by-step and, in S4040, narrow-down character recognition processingunit 310 carries out the Nth stage of the narrow-down process. In S4050,narrow-down character recognition processing unit 310 calculates anoptimum operating frequency based on operating frequency informationcorresponding to the result of the narrow-down process and then sets thecalculated frequency in power management unit 500.

In S4060, narrow-down character recognition processing unit 310 carriesout a detail-check process. In S4060, by the detail-check process forthe narrow-down candidate, the result of recognition is confirmed to endthe character recognition processing. After the process in S4060, thecharacter recognition process is returned to S4100 in FIG. 11.

An operation of the character recognition device in this embodimentbased on the above-described structure and flowchart is described below.

A user enters handwriting data from data input unit 200 (YES in S300),and then coordinate data is input to narrow-down character recognitionprocessing unit 310 to start recognition processing (S4000). Featureparameters are extracted (S4010), the first stage (S4020) of thecandidate narrow-down process is performed and, power management unit500 is controlled in such a way that an optimum operating frequency isset based on operating frequency information corresponding to the resultof the candidate narrow-down process (S4030). This process is repeatedand power management unit 500 is controlled to set a lower operatingfrequency each time the narrow-down number of candidates is decreased.Detail-check process is carried out (S4060) and the characterrecognition processing is completed.

As discussed above, the character recognition device in this embodimentadds, to the character recognition dictionary, operating frequencyinformation corresponding to the narrow-down number of candidates for acharacter to be subjected to character recognition processing.Accordingly, the narrow-down character recognition processing unit canset an optimum operating frequency according to the number of candidatesnarrowed-down in the character recognition processing thereby avoidingprocessing at an unnecessarily high speed. Moreover, the operatingfrequency is set as low as possible and thus the power consumption canbe reduced.

Fifth Embodiment

A character recognition device according to a fifth embodiment of thepresent invention is hereinafter described.

FIG. 13 shows a control block diagram of the character recognitiondevice in this embodiment. It is noted that any component in the controlblock diagram shown in FIG. 13 that is the same as the corresponding onein FIG. 1 is denoted by the same reference character, has the samefunction, and thus detailed description thereof is not repeated here.

As shown in FIG. 13, the character recognition device in this embodimentincludes a control unit 640 executing a program different from that ofcontrol unit 600 of the character recognition device in theabove-discussed first embodiment, and a character recognition dictionary100 storing operating frequency information 940 different from operatingfrequency information 900 in the first embodiment. The characterrecognition device in this embodiment further includes a predictioninput unit 2000. Additionally, the character recognition device in thisembodiment includes a prediction character-recognition processing unit320 carrying out processing different from that of character recognitionprocessing unit 300 of the above-described first embodiment.

Prediction input unit 2000 predicts, from the result of recognition byprediction character-recognition processing unit 320, characters whichare subsequently input. Prediction character-recognition processing unit320 can designate candidates for the character to be recognized in thecharacter recognition process. In other words, the result of recognitionby prediction character-recognition processing unit 320 is input toprediction input unit 200, and candidates for the character that maysubsequently be entered can be obtained.

FIG. 14 shows operating frequency information 940. As shown in FIG. 14,operating frequency information 940 includes operating frequencies thatare stored for respective numbers of candidates that are narrowed-downby prediction input unit 2000. For example, the frequency settinginformation is stored in such a way that, if the narrow-down number ofcandidates determined by prediction input unit 2000 is “20”, theoperating frequency is “FD (2)”. Here, as shown in FIG. 14, a loweroperating frequency is set for a smaller narrow-down number ofcandidates determined by prediction input unit 2000.

Referring to FIG. 15, a control structure of a program executed bycontrol unit 640 of the character recognition device in this embodimentis described. It is noted that any process step in the flowchart shownin FIG. 15 that is the same as the corresponding one in FIG. 2 isindicated by the same step number, the processing therein is the same,and thus detailed description thereof is not repeated here.

In S5000, control unit 640 calculates an optimum operating frequencybased on operating frequency information corresponding to the number ofcandidates that is supplied from prediction input unit 2000 and thensets the calculated frequency in power management unit 500. In S5100,control unit 640 inputs coordinate data obtained from data input unit200 as well as candidates obtained from prediction input unit 2000 toprediction character-recognition processing unit 320, and recognitionprocessing is performed.

In S5200, control unit 640 uses recognition result output unit 400 tooutput the result of recognition by prediction character-recognitionprocessing unit 320. In S5300, control unit 640 inputs the result ofcharacter recognition to prediction input unit 200 to obtain candidatesfor a character to be entered subsequently.

An operation of the character recognition device in this embodimentbased on the above-discussed structure and flowchart is described below.A user enters handwriting data from data input unit 200, an optimumfrequency is then calculated based on operating frequency informationcorresponding the number of candidates obtained from prediction inputunit 2000. The calculated operating frequency is set in power managementunit 500 (S5000).

Coordinate data input to data input unit 200 as well as candidatesobtained from prediction input unit 2000 are input to predictioncharacter-recognition processing unit 320 and then character recognitionprocessing is carried out (S5100). The result of the characterrecognition by prediction character-recognition processing unit 320 isinput to prediction input unit 2000 and candidates for the character tobe entered subsequently are obtained (S5300).

As discussed above, the character recognition device in this embodimentincludes, in the character recognition dictionary, the operatingfrequency information corresponding to the number of candidates obtainedfrom the prediction input unit. The control unit can set an optimumoperating frequency according to the number of candidates determined bythe prediction input unit. Accordingly, processing at an unnecessarilyhigh speed can be avoided. Moreover, the operating frequency can be setas low as possible to reduce the power consumption.

Sixth Embodiment

A character recognition device according to a sixth embodiment of thepresent invention is hereinafter described.

As shown in FIG. 16, a power management unit 510 of the characterrecognition device in this embodiment has a structure different fromthat of power management unit 500 of the character recognition device inthe above-discussed first embodiment.

Referring to FIG. 16, power management unit 510 of the characterrecognition device in this embodiment further includes an operatingvoltage changing unit 530 in addition to an operating frequency changingunit 520. In the first to fifth embodiments described above, powermanagement unit 3500 includes only the operating frequency changing unit520 and no operating voltage changing unit 530. Power management unit510 of the character recognition device in this embodiment havingoperating voltage changing unit 530 performs a voltage changing processby operating voltage changing unit 530 to lower the operating voltagewhen the operating frequency is low, in addition to the process ofsetting an optimum operating frequency.

As discussed above, the power management unit of the characterrecognition device in this embodiment changes the operating voltage andaccordingly power consumption can be reduced.

Seventh Embodiment

A voice recognition device according to a seventh embodiment of thepresent invention is hereinafter described.

Referring to FIG. 17, the voice recognition device in this embodimentincludes a voice recognition dictionary 3100 storing operating frequencyinformation 3900 as well as information for voice recognition, a voicedata input unit 3200 by which a user enters voice data, a voicerecognition processing unit 3300 performing voice recognition processingbased on the voice data entered from voice data input unit 3200 and theinformation stored in voice recognition dictionary 3100, a recognitionresult output unit 3400 which outputs the result of voice recognition byvoice recognition processing unit 3300, a control unit 3600 controllingvoice recognition dictionary 3100, voice data input unit 3200, voicerecognition processing unit 3300, recognition result butput unit 3400and power management unit 3500 via a control line 3700, and a powermanagement unit 3500 managing the operating frequency and operating modeof voice data input unit 3200, voice recognition processing unit 3300and recognition result output unit 3400 via a control line 3860.

Operating frequency information 3900 stored in voice recognitiondictionary 3100 includes an average dock number required for therecognition processing and an average process time corresponding to anoperating frequency, for example, according to the number of wordsregistered in voice recognition dictionary 3100.

Control unit 3600 uses operating frequency information 3900 to calculatean optimum operating frequency and set the calculated operatingfrequency in power management unit 3500. The optimum operating frequencyhere refers to a minimum operating frequency required for keeping anaverage time for voice recognition processing within a predefined time.The voice recognition process time depends on the number of words to berecognized that are registered in voice recognition dictionary 3100.Then, as the operating frequency information, a smaller clock number isstored for a voice recognition dictionary containing a smaller number ofwords to be recognized.

Referring to FIG. 18, a control structure of a program executed bycontrol unit 3600 of the voice recognition device in this embodiment isdescribed.

In S7100, control unit 3600 calculates an optimum operating frequencybased on the operating frequency information stored in voice recognitiondictionary 3100 and sets the calculated frequency in power managementunit 3500. In S7200, control unit 3600 instructs voice data input unit3200 to take voice data.

In S7300, control unit 3600 determines whether data is entered or not.If data is entered (YES in S7300), the process proceeds to S7400. If not(NO in S7300), the process proceeds to S7500.

In S7400, control unit 3600 inputs the voice data to voice recognitionprocessing unit 3300 to perform recognition processing.

In S7500, control unit 3600 determines whether or not data is enteredinto voice data input unit 3200 in a predetermined period. If data isnot entered into voice data input unit 3200 in the predetermined period(NO in S7500), the process proceeds to S7700. If data is entered (YES inS7500), the process is returned to S7200 and the voice recognitionprocessing is repeatedly performed for voice data entered into voicedata input unit 3200.

In S7600, control unit 3600 uses recognition result output unit 3400 tooutput the result of recognition by voice recognition processing unit3300. The process is thereafter returned to S7200.

In S7700, control unit 3600 instructs power management unit 3500 to stopclock generation, namely to shift the operating mode of this voicerecognition device to a low-power mode.

In S7800, control unit 3600 determines whether or not the operating modeshould be returned to a normal mode. If the mode should be returned tothe normal mode (YES in S7800), the process proceeds to S7900. If not(NO in S7800), the process is returned to S7800 to wait for the timingof returning to the normal mode.

In S7900, control unit 3600 instructs power management unit 3500 toresume dock generation. After this, the process is returned to S7200.

An operation of the voice recognition device in this embodiment based onthe above-discussed structure and flowchart is described below.

Based on the operating frequency information stored in voice recognitiondictionary 3100, an optimum operating frequency is calculated. Thecalculated operating frequency is set in power management unit 3500(S7100). Accordingly, voice data input unit 3200, voice recognitionprocessing unit 3300 and recognition result output unit 3400 that aremanaged by power management unit 3500 are controlled to operate at theoperating frequency set in power management unit 3500.

A user enters voice data by means of voice data input unit 3200 (YES in5300), the voice data is input to voice input processing unit 3300 andthe recognition processing is performed (S7400). The result ofrecognition by voice recognition processing unit 3300 is output by meansof recognition result output unit 3400.

In such an operation as described above, if no voice data is entered bya user from voice data input unit 3200 in a predetermined period (NO inS7500), power management unit 3500 stops dock generation and shifts theoperating mode of the voice recognition device to the low-power mode(S7700). When it is determined that the operating mode should bereturned to the normal mode upon pushing of a specific button by theuser while the device operates in the low-power mode (YES in S7800),power management unit 3500 resumes dock generation.

As discussed above, the voice recognition dictionary of the voicerecognition device in this embodiment includes the operating frequencyinformation. When the voice recognition dictionary contains a smallnumber of words to be recognized, the control unit sets a loweroperating frequency in the power management unit. Power consumption canaccordingly be reduced.

In the voice recognition device in this embodiment, as the characterrecognition device in the above-discussed first embodiment, voicerecognition dictionary 3100 may be in the form of a memory card which isdetachably held in the voice recognition device. At this time, memorycards may have respective different languages to be recognized in thevoice recognition.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

1-7. (canceled)
 8. An information recognition device performingrecognition processing on voice comprising: an input unit for enteringvoice data representing voice to be subjected to said recognitionprocessing; a storage unit storing first information required for voicerecognition by a voice recognition module and second informationconcerning power consumption of said information recognition device thatis set according to voice to be recognized; the voice recognition modulerecognizing voice based on the voice data entered from said input unitand said first information stored in said storage unit; an output unitoutputting the voice recognized by said voice recognition module; apower management unit managing power consumption of said informationrecognition device; and a control module controlling said powermanagement unit based on the second information stored in said storageunit.